(a) Field of the Invention
The present invention relates to a method of forming a pattern on a substrate and a method of manufacturing a liquid crystal display panel using the same.
(b) Description of the Related Art
Generally, a liquid crystal display (LCD) includes two panels provided with electrodes, and a liquid crystal layer interposed between the two panels. The electrodes generate electric field to be applied to the liquid crystal layer interposed between the panels and the LCD displays images by adjusting the field strength to control the transmittance of light passing through the panels.
Photo etching processes are performed to form various patterns on the panels of the LCD through light exposure using a stepper or an aligner.
The stepper uses a small mask suitable for its equipment characteristics and the light exposure is performed by partitioning the panel into several shots and exposing the shots to light While moving the panel to up ward and downward and right and left under the mask for the stepper. The mask for the stepper is aligned with the panel by aligning the mask with the stepper and aligning the panel with the stepper.
The aligner exposes the entire area of the panel to light with one shot using a large mask in accordance with the equipment characteristics. At that time, after a mask for the aligner is aligned with the aligner, the panel is aligned with the mask for the aligner. When the LCD is manufactured, the aligner profitable to the production line manufacturing large panels is adapted.
However, as the LCD panel to be manufactured becomes too large to use the conventional aligner, it becomes hard to expose the large LCD to light by one shot using one mask. The mask exposure is accomplished by repeating a divisional exposure. One divisional exposure unit or area is called a shot.
Since transition, rotation, distortion, and etc. are generated during light exposure, the shots are not aligned accurately. Accordingly, parasitic capacitances generated between wires and pixel electrodes differ depending on the shots, and this causes the bright difference between the shots, which is recognized at the pixels located at a boundary between the shots. Therefore, the stitch defect is generated on the screen of the LCD due to brightness discontinuity between the shots.
Thus, when a large LCD is manufactured from a large panel, the stitch defect is inevitable even though the exposure process is performed using the aligner. In particular, the exposure processes for forming the respective patterns of the LCD use respective masks which give the same shots. Accordingly, the boundaries of the shots for the respective patterns coincide to multiply generate the stitch defect of the display.